Polar Vortex

Introduction

Over the past several weeks, beginning in December 2013 into January 2014, the mass media has been flooded with the buzz word “Polar Vortex”. Most of us have never even heard of a Polar Vortex, even though it has been a well documented and studied weather phenomenon for well more than a century, at least as early proper weather records were begun in the 1800’s. Mankind has been acutely aware of weather conditions since the ancients and records have been kept, but not maintained in any systematic orderly manner as to predict weather patterns and conditions.

The first concept as to what a Polar Vortex is would be the recognition that it is a global condition observed based upon spatial data obtained from real time measurement. With the advent of precise and more accurate weather instrumentation data synthesis has become sophisticated. Computer statistical and analytical modeling has enabled a complex array of hypothesis to explain the weather machine. But it’s the earlier grass roots studies and evaluations which have laid the foundation for modern climatology. For example, the recognition of the Jet Stream, Gulf Stream, La Nina’ and other global traits were derived from mathematical treatment of observed data. In the case of a Polar Vortex, the most comprehensive basis would be “The International Standard Atmosphere (ISA)”, which is an atmospheric standard for how the pressure, temperature, density, and viscosity of the Earth’s atmosphere change over a wide range of altitudes. The key word here is altitude.

Explanation of the Term

Polar vortices, also termed polar cyclones, are climatological features occurring year round in locations near both the Earth’s geographical poles. On Earth, the polar vortices are located in the middle and upper troposphere and the stratosphere. These cold low-pressure areas strengthen in the winter and weaken in the summer due to their reaction to temperature differential between the equator and the poles. This is the same process which establishes the seasonal configuration of the Jet Stream and Gulf Stream. These polar lows occur in both hemispheres, and rotate as a cyclone does in response to the Coriolis effect. They usually cover an area of over a 1,000 kilometers at their greatest expanse, often preceded by a lowering of the Jet Stream from northern Canada into the US with an accompanying strengthening of the Gulf Stream, or the classic “Nor-Easter”.

Polar Vortex Schematic

Typical Polar Vortex Positions

Common Public Domain.

Barometric Isopleths

Contour Map of Low Pressures

Common Free Domain.

As you can discern from the above figures, there is nothing here any different from a typical winter in the Northern Hemisphere, some are just more severe as a testament to cyclic weather patterns recorded in the data base. Just how cyclic globally is another matter. The bottom figure looks like a normal weather map you see in the media, with barometric highs, lows, fronts and troughs, albeit on a hemispheric scale. The Arctic oscillation is an index which is mostly used to evaluate cyclic patterns.

The Polar Vortex and Global Warming

The above discussion is based upon basically weather pressure differentials. Not included are analyses of other weather variables, such as temperature, precipitation, wind, Earth’s rotation (Coriolis effect is just mentioned), and a myriad of thermal dynamic and differential equation concepts. All of these are pertinent to an understanding of global warming. To single out a Polar Vortex as a common denominator for or against global warming is not soundly based. A Polar Vortex is normal. It’s effect may differ, or it may have cyclic implications, but it alone is neither a basis for or against global warming. The question of whether the Earth’s climate is changing globally is not a question, it’s a fact. The last Ice Age was a mere 12,000 years ago, and the planet is still responding to a global thaw. So the fact that the Arctic and Antarctic are losing their ice packs is not surprising. The surprise is the rate in which the climate is changing at the poles. Just how much humankind has escalated the process is the real debate on Global Warming. It may be that the Polar Vortex will become an important symptom indicator once the cyclic nature is better understood. The common notion that these polar cyclones prove Global Warming is a hoax would not be justified. Most climatological models actually predict changes in the Polar Vortex, including increases in winter severity within the Global Warming concept.

References
http://en.wikipedia.org/wiki/Polar_vortex

“The Polar Vortex and Arctic Weather Patterns”.

Arctic Climatology and Meteorology

. Retrieved January 29, 2005. “GEOS-5 Analyses and Forecasts of the Major Stratospheric Sudden Warming of January 2013” (Press release). Goddard Space Flight Center. Retrieved January 8, 2014.http://adsabs.harvard.edu/abs/1992JGR….97.7859S

“Polar Vortex”. Glossary of Meteorology. American Meteorological Society. April 2012. Retrieved January 7, 2014.

www.cnn.com/2014/01/06/us/polarvortex-explained/index.html

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